British actor Benedict Cumberbatch re-ignited his smoking habit to lower his voice for a new film role.The War Horse star gave up tobacco several years ago, but decided to start puffing on cigarettes again while preparing for upcoming musical City Of Angels, which harks back to the age of film noir detective movies. He says, "In order to get the whole film noir detective thing I smoked a lot and drank a lot of whisky. "I used to smoke quite a bit and it deepened my voice."